1. Field of the Invention
The present invention is for a constant velocity flexible coupling, and more particularly pertains to a flexible disc coupled mechanism similar in function to a universal drive joint for use in 4-wheel drive steer devices, such as a 4-wheel drive lawn mower or other such vehicles.
2. Description of the Prior Art
Four-wheel drive and steer mechanisms have been reserved for high end expensive commercial and industrial equipment ranging in the tens of thousands of dollars. The methods used to achieve power delivery through a pivoting steerable mechanism are effective and durable, but not in the same class as the smaller and more inexpensive and smaller lawn tractors intended for general consumer use. The cost is high and many do not even use CV-joints. Four-wheel drive farm tractors and utility tractors use designs far too expensive and are similar in design to units utilized in front wheel drive cars.
Another problem with prior art devices is that of offering a low speed flexible coupling that can function effectively up to 50.degree. angles and yet fit in a relatively short (axial) space and require no sliding connections such as splines for absorbing axial reciprocation. The present invention uses no such spline devices and as such can be fabricated for a much more reasonable price. Four-wheel drive/steer mechanisms have been incorporated in some prior art lawn tractors, but steering and drive devices have limited the steering angle to a low range of steering at approximately 20.degree..
Although disc-type flexible joints are not new, the turning radius of single disc-type flexible joints are limited by the geometry of the single flexible disc. The present invention overcomes this problem by utilizing two flexible disc members coupled by an intermediate joint connector about which both discs flex.
Clearly, what is needed is an inexpensive, yet effective and durable drive steer coupling providing for an increased turn angle for use in small vehicles, such as provided by the present invention.